Vat dyestuffs



"the halogen-free products can already be ob-,-. The dyestuffs of the invention are suitable for Patente 1951. 2 539 193 UNITED STATES PATENT OFFICE VAT DYESTUFFS Walter Kern, Sissach Switzerland, assignor to Ciba Limited, Basel, Switzerland, a Swiss firm No Drawing. Application March 8, 1949, Serial No. 80,325. In Switzerland March 16, 1948 6 Claims. (Cl. 260-316) It is known to subject reaction products of served when the halogenation is such as to in- 518-diha1ogen-l :2-benzanthraquinones with amitroduce less than one halogen atom into the dyenoanthraquinones to the action of carbazolizing stuff. However, the halogenation may proceed to agents (see German Patent No. 536,294, French the stage at which more than one, for example, Patent No. 696,011, British Patent No. 335,014 and 5 about two halogen atoms, especially chlorine United States Patent No- 1,923,227). The startatoms, are introduced into the molecule. ing materials used in these patents are derived The treatment of the above described starting from l-aminoanthraqu-inon and aminoanthramaterials with carbazolizing agents of the type of quinones which contain as substituents in a-POSlaluminum chloride is advantageously conducted tion acylamino groups, especially benzoylamino in a solvent or dispersing medium, advantageousgroups. The dyestuffs obtained by these known ly in the presence of a tertiary base such as pyriprocesses dye brown tints. dine or a homologue of pyridine. The products According to the present invention valuable vat can be worked up in the usual manner. In some dyestuffs are made by treating a product of the cases it is of advantage after the carbazolization general formula to subject the dyestuff to vatting and then to regenerate the dyestufi by treatment with an oxidizing agent, for example, by introducing a blast Bz I O NH of air.

)K I The dyestuffs so obtained correspond to the general formula t NH in which R represents the radical of a 1:1'-dianthrimide linked to the NH-groups in ie-position and the Bz-nucleus may be halogen-substituted, with a carbazolizing agent of the type of aluminum chloride.

The products of the above formula used as starting materials in the present invention can be obtained in a simple manner, on the one hand, from 5 8-dihalogen-l: Z-benzanthraquinones, advantageously from 5:8-dibromoor more especially 5: 8-dichloro-1 Z-benzanthraquinone, and, on the other, from 1:l-dianthrimicles which are substituted by an amino group in 4-position, if in which the Bz-nucleus may with advantage be desired, with the addition as an agent assisting halogen-substituted and in which other substitthe reaction in known manner of copper or a uents not harmful in vat dyestuffs may be prescop'per salt such as copper acetate. Especially ent. Among these vat dyestuffs there are espeadvantageous results are obtained by using star cially advantageous those of the above general i'ng materials which are derived from e-aminoformula in which no other substituents are pres- 1 :1-dianthrimides containing no or only few furent. These dyestuffs are in general distinguished ther substi'tuen-ts, especially 4-amino-i:ldianby yielding tints which are moderately or to a thrimide itself. considerable extent neutral grey. In view of the Especially valuable dyestuffs are obtained by fact that a grey tint is the consequence of a dyeusing starting materials which are halogen-sud stufi having a rather uniform absorption curve,

stituted in the Bz-nucleus. Such starting and that the majority of all dyestuffs do not ex rials are obtained in a simple manner by halo- PM hibit a uniform absorption in the visible region genating the corresponding halogen-free prodof the spectrum, but Show pronounced absorption ucts, for example, with the use of brominating or maXima, it could not be expected that the dyechlorinating agents such as bromine or especially stuffs of the present invention would yield grey sulfuryl chloride. A difference as compared with tints.

dyeing and printing a very wide variety of materials, especially vegetable fibers such as cotton, linen and artificial silk and staple fibers of regenerated cellulose. They can be used in the form of the leuco-ester salts (for example, the sulfuric acid salts) obtainable in the usual manner for dyeing and printing by the customary methods for this class of dyestuffs.

The following examples illustrate the invention the parts and percentages being by weight unless otherwise stated and the relationship of parts by weight to parts by volume being the same as that of the kilogram to the liter:

Example 1 2 parts of the condensation product from 1 mol of :8-dichlor0-2:l-benzanthraquinone and 2 mols of 4-amino-1:l-dianthrimide and having the formula are introduced at 100 G. into a mixture of 8 parts of aluminum chloride and 16 parts of pyridine, and the whole is stirred for 2 hours at 125-l30 C. The melt is then poured into water, and the mixture is rendered alkaline with caustic soda solution. The product is vatted with hydrosulfite, the mixture is filtered to remove a small amount of residual matter and air is blown through the dyestufl'. It is a dark powder which dissolves in concentrated sulfuric acid with a brown-olive coloration and dyes cotton from a yellow-brown vat fast grey tints of a slight olive shade. The starting material used in this example is prepared as follows:

6.5 parts of 5:8-olichloro-l:2-benzanthraquinone (obtained by subjecting to ring closure the reaction product of naphthalene and 3:6-dichlorophthalic anhydride by treatment with phosphorus pentoxide in ortho-dichlorobenzene as indicated in Example 1 of British Patent No. 332,192), 17.9 parts of 4-amino-1:1-dianthri mide, 4.4 parts of anhydrous sodium carbonate and 0.4 part of copper acetate in 180 parts of nitrobenzene are maintained at the boil for 8 hours. After cooling, the condensation product which has precipitated in a quantitative yield is separated by filtration, washed and extracted at the boil with dilute hydrochloric acid. It is a green-black crystalline powder, which dissolves in concentrated sulfuric acid with a green-olive coloration. Its nitrogen content is 4.91 per cent. (4.89 per cent. being required by theory).

Example 2 2.5 parts of the condensation product from 1 Incl of 5:S-dichloro-l:Z-benzanthraquinone and 2 mols of 4-amino-l:1-dianthrimide are introduced at 100 C. into a melt consisting of 12.5

parts of aluminum chloride and 28 parts of dry pyridine. The temperature is then rais 0 -132 C. while simultaneously distilling a part of the pyridine, and the whole is stirred at that temperature for 1 hour. The reaction mass is then introduced into water, and is rendered alkaline with caustic soda solution and vatted with hydrosulfite. After filtration to remove a small amount of residual matter, air is blown through the dyestuff-solution, and the latter is separated by filtering with suction, washed and dried. It is a dark powder which dissolves in concentrated sulfuric acid with a brown-olive coloration, and dyes cotton from a yellow-brown vat fast grey tints having a slight olive shade.

Practically the same dyestuff is obtained when the portion of the pyridine is first removed from the aluminum chloride-pyridine mixture by dis tillation, and then the condensation product of 5 B-dichloro-l :Z-benzanthraquinone and 4-amino-l:1'-dianthrimide is added at 12l-l23 C. and the whole is stirred at that temperature for 1 hour. By after-oxidation with sodium bichromate the tint of the dyestuff becomes somewhat browner in shade.

Example 3 and which dissolves in concentrated sulfuric acid with a brown-olive coloration and dyes cotton from a yellow-brown vat grey tints havingexcellent fastness properties.

- Example 4 By more powerfully chlorinating the condensation product of the last paragraph of Example 1 at a higher temperature 2 atoms of chlorine enter the molecule. By fusing the resulting product with aluminum chloride and pyridine as described in paragraph 1 of Example 2 a dyestuff is obtained which dissolves in concentrated sulfuric acid with a brown-olive coloration and dyes cotton from a yellow-brown vat grey tints of excellent fastness.

Example 5 6.6 parts of 5:8-dichloro-1:2-benzanthraquinone are condensed with 17.8 parts of 4- amino-1:l'-dianthrimide as described in the last 7 paragraph of Example 1 and the reaction mass 5. is cooled t"40' C. Thus, 9.6 parts of bromine and, a small (catalytic) quantity of iodine are added and the mixture is stirred at 40-45 C. for 14 hours, then at 65-70 C. for 16 hours. After filtration, washing and boiling with dilute hydrochloric acid a blackish violet powder is obtained which dissolves in concentrated sulfuric acid with an olive-green coloration and has a brominev content of about 6.4 per cent.

parts of this product are introduced at 100 0. into a melt consisting of 25 parts of aluminum chloride and 56 parts of anhydrous pyridine. The. temperature is then raised to 139-142" C. While distilling a .part of the pyridine, and the whole is stirred at that temperature for one hour. The. reaction mass is then introduced into water, and is rendered alkaline with caustic Soda solution and, vatted with hydrosulfite. After filtration to remove a small amount of insoluble matter air is blown through the vat and the dyestuif is suction-filtered, washed and dried. It is-a dark powder which corresponds to the formula Emample 6 1.5 parts of the dyestuff obtained as described in Example 3 are vatted in 200 parts of water with 5 parts by volume of caustic soda solution of 36 B. and 2.5 parts of sodium hydrosulfite at about 50 C. The resulting stock vat is added to a dyebath which contains in 2800 parts of water parts by volume of caustic soda solution of 36 B. and 5 parts of sodium hydrosulfite. 100 parts of cotton are entered at 40 C., 45 parts of sodium chloride are added after minutes, and dyeing is carried on for 1 hour while heating the dyebath up to 50 C. The cotton is then squeezed, oxidized in the air, rinsed and finished in the usual manner. It is dyed a fast grey tint.

It is to be understood that in the appended claims the symbol haln 0 means substitution and not addition of hal for hydrogen atoms otherwise present in the benzene ring, the index 11, indicating the number of atoms so substituted.

What I claim is: Y 1. A vat dyestuff of the general formula wherein each A1 and each A2 stands for an anthraquinone radical, A1 carrying the NI-Lgroups in 1- and l-positions, respectively, and the link completing the carbazole ring in 2- and 3-positions, respectively, and A2 carrying the Nl-I- roup in l-position and the link completing the carbazole ring in 2-position, and wherein hal stands for a halogen and n for a number between 0 and inclusive.

2.. A vat dyestuff of the general formula hal O 5. The vat dyestufi of the formula 6. The vat dyestufi of the formula k m k/ I A NH-- NH 6 WALTER KERN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,923,227 Nawiasky et a1 Aug. 22, 1933 2,364,456 Lulek Dec. 5, 1944 

1. A VAT DYESTUFF OF THE GENERAL FORMULA
 4. THE VAT DYESTUFF OF THE FORMULA 